<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <div>
        <p>1</p>
        <p>2</p>
    </div>
<script>
    let po = document.querySelector('div p');
    po.style.color = 'blue';
</script>
</body>
</html>